I was asked to make a lid for a large urn type vessel. I cut the lid and handle on the ShopBot. The edge profile on the lid was done with a 1" bullnose bit on the router table. As the bit had no bearing I cut a fence from scrap MDF with a diameter that matched the lid.
I've come to realize that not every operation needs to be done on the CNC, but I was wondering how I could have done this operation on the CNC. I realize hold down would be an issue and the lid would need to be elevated above the spoilboard. I guess this could be done with some form of vacuum pod. Specifically I was wondering how this cut would be programmed in VCarve/Aspire. Would you use the "lead" in a profile cut? How would you plunge the bit to the full depth? How would you make the cut in more than one pass, given that each pass would be a circle of smaller diameter?
This particular bit would be a pretty aggressive example of this type of cut, but I'm sure there are plenty of other edge profile bits that could be used to machine on the edge of the material instead of just the top of the material. Any insight as to how to get started on this would be appreciated.